We are deep in the tea mountains of Xishuangbanna Prefecture in China’s Yunnan Province. Villages inhabited by the Dai, Bulang, Lahu, Akha, and other ethnic minorities lie across ravines or peek out from the forest. Glancing up a hillside, I spot people perched in the uppermost branches of some tea trees.

Our driver pulls over, four of us climb out of the car, and then we hike up a narrow path to reach the workers. The women wear scarves—some handwoven, some embroidered, and some decorated with silver balls and other trinkets. The men’s faces are cragged and as dark as saddle leather from lifetimes spent in the sun. We pepper them with questions: How old are these tea trees? How many generations has your family worked as tea pickers? Do you process your own tea? These folks don’t seem too surprised to see us or to hear our questions. It’s tea-picking season in Yunnan’s tea mountains, and over the past few years more and more visitors, including myself, have come in search of Pu’erh tea—the most valuable and collected of all the world’s teas—and to explore the birthplace of tea.

Tea is the second most popular drink in the world after water. It was discovered in 2737 B.C. by Emperor Shen Nung—also known as the “Divine Husbandman”—when some tea leaves accidentally blew into his pot of hot water, or so the legend goes. For more than 4,700 years, tea has traveled the world, so that today it’s grown in India, Nepal, Japan, Kenya, and other mountainous countries between the Tropics of Cancer and Capricorn. Tea takes many forms—black, green, oolong, dark, white—but they all come from an evergreen plant called Camellia sinensis. For centuries, tea has been used as a form of money and to pay tribute. It has also been taxed as a precious commodity. (Any American fifth grader can tell you about the dramatic role tea played in Boston Harbor in the years leading up to the Revolutionary War.) Tea is also central to China’s three great schools of philosophical thought. Confucius taught that tea could help people understand their inner dispositions. Buddhists believe that drinking tea is one of the four ways to concentrate the mind—along with walking, feeding fish, and sitting quietly—to help link people to the realms of meditation. Taoists say that tea, which they accept as an ingredient in the elixir of immortality, puts you in harmony with the natural world. In other words, tea drinking is infused throughout every aspect of life in China. It’s a part of every day and for every level of society.